Cleansing composition and method

ABSTRACT

A CLEANSING COMPOSITION FOR REMOVING OILS, GREASES DUST, DIRT AS WELL AS WATER FROM NON-POROUS OBJECTS TO PREPARE THEM FOR PHOSPHATIZING, ELECTROPLATING, ENAMELING, GLAZING, LACQUERING OR PAINTING WHICH COMPRISES A CHLORINATED ETHYLENE SUCH AS TRICHLOROETHYLENE OR PERCHLOROETHYLENE, FROM 0.1 TO ABOUT 1.5 PERCENT BY WEIGHT OF A NON-IONIC SURFACE ACTIVE AGENT, SUCH AS AN ADDITION PRODUCT OF ETHYLENE OXIDE WITH AN ALKYL PHENOL, FATTY ALCOHOL OR FATTY ACID, AND PREFERABLY 2 TO 100 PARTS PER MILLION OF AN AMINE FIXER, E.G., AN ALIPHATIC OR AROMATIC AMINE. THE METHOD OF CLEANSING INVOLVES IMMERSING THE OBJECTS IN THIS COMPOSITION WHILE IT IS BOILING AND THEN TRANSFERRING THEM TO A BOILING, PURE CHLORINATED HYDROCARBON.

United States Patent 3,573,212 CLEANSING COMPOSITION AND METHOD RafaelFoguet Ambros, Flix, Spain, assignor to Electr0- Quimica de Flix, S.A.,Barcelona, Spain No Drawing. Filed Jan. 9, 1968, Ser. No. 696,511 Int.Cl. Clld 1/18, 1/38, 1/50, 3/26 US. Cl. 252-153 9 Claims ABSTRACT OF THEDISCLOSURE A cleansing composition for removing oils, greases, dust,dirt as well as water from non-porous objects to prepare them forphosphatizing, electroplating, enameling, glazing, lacquering orpainting which comprises a chlorinated ethylene such astrichloroethylene or perchloroethylene, from 0.1 to about 1.5 percent byweight of a non-ionic surface active agent, such as an addition productof ethylene oxide with an alkyl phenol, fatty alcohol or fatty acid, andpreferably 2 to 100 parts per million of an amine fixer, e.g., analiphatic or aromatic amine. The method of cleansing involves immersingthe objects in this composition while it is boiling and thentransferring them to a boiling, pure chlorinated hydrocarbon.

The importance of the chlorinated solvents, trichloroethylene andperchloroethylene in modern industry is well known. Fundamentally theseare the solvents which otherwise are generically known as metaldegreasers, although the method also applies to non-metallic objects.

The material to be degreased consists of finished or semi-finishedobjects of all kinds which have been manufactured with the aid ofcooling, cutting or lubricating products. Sometimes the surfaces arecontaminated by shavings, sawdust, oils, greases, talcum, etc. whichmust be removed completely.

It is frequently necessary, in the metal working industry, e. g., in themanufacture of electrical appliances, metal coverings, automobileaccessories, photographic apparatus, engravings, jewelry and costumejewelry, clocks and Watches, metal locks, bearings and apparatus ingeneral, as well as in the electrical industry, to have recourse tosurface treatment preliminary to phosphatizing, electroplating,enameling, glazing, lacquering or even mere painting.

All these techniques are based on adherence and compactness of thecoating which is directly influenced by the cleanliness of the surfaceto which it is applied. Any dirt or spot of moisture makes the coatingdefective no matter how soundly and carefully it is carried out.

It is customary in the surface treatment of such objects to use aqueoussolutions, including even water, to eliminate traces of acids oralkalis. For a quality coating, any water remaining on the object to betreated is as damaging as the dirt which was previously removed. Theadherence of a protective layer is excellent only when it is applied toan absolutely clean surface, free of water and the salts dissolvedtherein, which at times form spots.

One conventional manner of drying, namely blowing with hot air orcombustion gases, does not provide a satisfactory solution for thisproblem. Although it causes evaporation of the water, the saltsdissolved therein remain on the object and form the above-mentionedundesirable spots.

The use of organic liquids (non-chlorinated solvents) Which have anaffinity for water and which have a high vapor tension at lowtemperature to facilitate rapid drying, enormously complicates theproblem since in general these liquids are combustible and excessivelylight. Their use requires special closed apparatus provided with safetymechanisms in order to avoid accidents. Conventional sol- 3,573,212Patented Mar. 30, 1971 vents for the degreasing of metals, i.e.,chlorinated hydrocarbons such as trichloroethylene andperchloroethylene, have the advantage of making it possible to work withopen apparatus due to the substantial density of their vapors. However,these two solvents in themselves have little affinity for water andtherefore act very slowly to eliminate water adhering to the surface ofan object, even at temperatures above room temperature.

It has now been found that it is possible to increase the affinity ofsuch solvents for water by the addition of a wetting agent andpreferably also a pH fixing agent. In the cleansing method of theinvention, the object contaminated by water or other contaminants isimmersed in a boiling mixture of solvent, wetting agent and pH fixer.The water passes rapidly into the mixture and is eliminated byazeotropic distillation.

Satisfactory results are in particular obtained when using, for thecleansing and drying of non-porous objects which contain water oraqueous solutions, compositions consisting of a chlorinated ethylene, anon-ionic surfaceactive agent and a pH fixer.

Large amounts of additives to the solvent are not necessary to obtaingood results; from 0.1 to 1.5% by weight of non-ionic surface-activeagent and from 2 to parts per million, by weight, of amine fixer aresufiicient.

Specifically, small proportions of additives must be used to avoidformation of emulsions and to permit rapid volatilization of the watertogether With the solvent forming the heteroazeotrope of minimum boilingpoint.

The non-ionic surface-active agents employed include for instanceoxyethylated products derived from alkyl phenols, fatty alcohols ofoxyethylated greases or derivatives of greases in general; among themthe addition products of ethylene oxide (from 4 to 30 mols per mol) tononyl phenol, addition products of ethylene oxide (20 to 50 mols permol) to tributyl phenol, addition products of ethylene oxide to octylphenol, addition products of ethylene oxide (more than 10 mols per mol)to lauric and myristic alcohols, or to their mixtures, addition productsof ethylene oxide (from 18 to 42 mols per mol) to castor oil, andaddition products of ethylene oxide to oleic acid deserve specialmention.

pH fixing agents that are useful in the composition and method of theinvention include, by way of example, aliphatic amines such as triethylamine, triethanolamine and diisopropyl amine, aromatic amines such asphenyl amine, diphenyl amine and naphthylamine.

The choice of trichloroethylene or perchloroethylene depends on variousfactors. Trichloroethylene must be avoided for treatments of aluminumand light metals, while perchloroethylene does not offer any chemicalincompatibility. On the other hand the use of perchloroethylene requiresbaths of higher temperature because of the higher boiling point C.) ofperchloroethylene.

The apparatus for carrying out the drying of nonporous objects are thosenormally used in the treatment of metal surfaces; i.e., apparatus havingone vessel or chamber containing the drying mixture and anothercontaining pure solvent, both being maintained at the boiling point. Theazeotropic mixture distilled from the first vessel or chamber passes toa water-solvent separator which returns the solvent to the chamber andeliminates the water.

EXAMPLE A drying solution is formed by adding to trichloroethylene orperchloroethylene A. from 0.1% to 1.5% nonionic surface-active agent,such as an addition product of ethylene oxide (from 4 to 30 mols permol) to nonylphenol; an addition product of ethylene oxide (20 to 50mols per mol) to tributyl phenol; an addition product of ethylene oxideto octyl phenol; an addition product of ethylene oxide (more than molsper mol) to lauric or myristic alcohols or a mixture thereof; anaddition product of ethylene oxide (from 18 to 42 mols per mol) tocastor oil; or an addition product of ethylene oxide to oleic acid, andB. from 2 to 100 parts per million of an amine such as triethyl amine,triethanolamine, diisopropyl amine, butylamine, phenyl amine, diphenylamine or naphthylamine.

This solution is maintained at a boil and the non-porous objects to bedried are immersedin it. In general 10 to 50 seconds is sufficient toeliminate the water or the spots thereof. The residues of thesurface-active agent are removed by immersion in a second chambercontaining pure solvent at the boiling point.

I claim:

1. Liquid cleansing composition consisting essentially of a chlorinatedethylene, from 0.1 to about 1.5% by weight of a non-ionic surface activeagent selected from the group consisting of addition products of 4-50mols per mole ethylene oxide and tributyl phenol, nonyl phenol, octylphenol, castor oil, lauric alcohol or myristic alcohol or mixturesthereof, and from 2 to 100 parts per million of an amine selected fromthe group consisting of triethyl amine, triethanolamine, diisopropylamine, phenyl amine, diphenyl amine and naphthylamine.

2. Method of cleansing the surfaces of a non-porous object whichcomprises immersing it in a boiling liquid composition as defined inclaim 1 for from 10 to 50 seconds and then transferring the object forimmersion in a boiling, pure chlorinated hydrocarbon.

3. Composition as defined in claim 1 wherein the chlorinated ethylene istrichloroethylene.

4. Composition as defined in claim 1 wherein the chlorinated ethylene isperchloroethylene.

5. Composition as defined in claim 1 wherein the nonionic surface activeagent is an addition product of ethylene oxide and nonyl phenol in amolar ratio of 4 to 1.

6. Composition as defined in claim 1 wherein the nonionic surface activeagent is an addition product of ethylene oxide and tributyl phenol in amolar ratio of 20 to :1.

7. Composition as defined in claim 1 whereinthe nonionic surface activeagent is an addition product of ethylene oxide and octyl phenol or oleicacid.

8. Composition as defined in claim 1 wherein the nonionic surface activeagent is an addition product of ethylene oxide and castor oil in a molarratio of 18 to 42: 1.

9. Composition as defined in claim 1 wherein the nonionic surface activeagent is an addition product of ethylene oxide and lauric or myristicalcohol in a molar ratio of more than 10:1.

References Cited UNITED STATES PATENTS 9/1958 Bloch et a1. 252-364 LEOND. ROSDOL, Primary Examiner W. E. SCHULZ, Assistant Examiner US. Cl.X.R.

